Powder for isolating infrared rays, and isolating solution and goods using the same

ABSTRACT

Disclosed is a novel concept of infrared blocking powder, that is to say, indium antimony tin oxide (IATO), which is produced by mixing indium (In), antimony (Sb), and tin (Sn) in a predetermined mixing ratio, and co-precipitating a mixture in solvent. Additionally, the present invention provides infrared blocking solution and infrared blocking material using the infrared blocking powder, which allow visible rays to transmit therethrough but effectively block near-infrared rays acting as thermic rays.

TECHNICAL FIELD

The present invention relates to a novel concept of infrared blockingpowder, that is to say, indium antimony tin oxide (hereinafter, referredto as “IATO”), which is produced by mixing indium (In), antimony (Sb),and tin (Sn) in a predetermined mixing ratio, and co-precipitating amixture in a solvent. Additionally, the present invention providesinfrared blocking solution and infrared blocking material using theinfrared blocking powder, which allow visible rays to transmittherethrough but effectively block near-infrared rays acting as thermicrays.

BACKGROUND ART

Of the various rays of the sun, having different wavelengths, anultraviolet ray with a wavelength of 150 to 380 nm functions to discolora substance or to damage a skin, and an infrared ray with the wavelengthof 780 to 2300 nm has heat energy corresponding to 53% of solar energy.Accordingly, there is a need to develop functional coating material(blocking material) capable of allowing a visible ray with thewavelength of 380 to 780 nm to easily transmit therethrough andeffectively blocking the ultraviolet and infrared rays.

A conventional sunlight blocking film for automobiles is disadvantageousin that it cannot be applied to the front windows of automobiles,through which heat is mostly transmitted, because of its poortransparency even though it can block the ultraviolet ray. Additionally,the conventional sunlight blocking film cannot effectively block heatoutside the automobiles, and thus, air conditioners of the automobilesare excessively used to cool insides of the automobiles in summer,leading to enormous energy consumption and serious pollution. In winter,indoor heat is mostly lost through windows, which brings about energywaste. To avoid heat dissipation, a transparent heat blocking film maybe attached to the windows.

In order to better understand the background art of the presentinvention, a description will be given of a conventional transparentcoated film capable of allowing the visible ray to easily transmittherethrough and blocking the infrared ray. Technologies regarding theconventional transparent coated film may be classified into a) a gasphase process, in which an indium tin oxide (hereinafter, referred to as“ITO”) film is formed according to physical and chemical depositionprocesses or a sputtering process, and b) another process usinganthraquinone-, naphthalocyanine-, cyanine-, phthalocyanine-, metalcomplex-, diammonium-, azo compound-, copper compound-, polymethine-,triphenylmethane-, and quinone-based pigments.

In detail, in the case of the gas phase process (a), it is necessary touse a high-priced sputtering device requiring high vacuum and highprecision, and thus, the gas phase process is disadvantageous in termsof the production costs and productivity. Furthermore, the process of b)is disadvantageous in that sufficient infrared blocking effect is notensured at a relatively wide wavelength range but only the infrared raywith a specific wavelength is blocked, a surface of the coated film isdiscolored due to UV, heat, moisture and the like, and an infraredblocking ability is not constantly secured.

To avoid the above disadvantages, there has been developed a compositionfor a near-infrared blocking filter, which is mass-produced atrelatively low cost, and which includes ITO ultrafine powder or antimonytin oxide (hereinafter, referred to as “ATO”) ultrafine powder, metaloxides, and organic and inorganic dyes and pigments (JP-A-7-24957,JP-A-7-70363, JP-A-70482, and JP-A-7-445).

However, the composition including the ITO and ATO ultrafine powders isdisadvantageous in that the transmissivity is relatively low within anear-infrared range with the wavelength of 1400 nm or more, but thetransmissivity is relatively high within the near-infrared range withthe wavelength of 701 to 1399 nm, and thus, it is difficult to secure adesirable infrared blocking effect.

Furthermore, in case that a metal oxide and a metal form a multilayeredstructure according to the sputtering process, even though an infraredblocking effect is improved, the productivity is poor, the productioncosts are relatively high, and the multilayered structure reflectssunlight, bringing about a dazzling phenomenon. In addition, themultilayered structure leads to a wave phenomenon in night, therebyhindering any view. As well, it is easily corroded in a zone, at whichair contains a great amount of salt.

Recently, many studies have been made to develop a process usingnear-infrared absorbing dyes and pigments. However, this process hasdisadvantages in that sufficient infrared blocking effect is not ensuredat the relatively wide wavelength range but only the infrared ray withthe specific wavelength is blocked, the surface of the coated film isdiscolored due to UV, heat, moisture and the like, and the infraredblocking ability is not constantly secured.

Additionally, a glass filter, on which a metal film is deposited, and aphosphate glass filter, containing metal ions, are well known to thoseskilled in the art. However, these glass filters are insufficientlycompetitive in terms of production costs.

Generally, a process of producing the ITO powder includes reacting anaqueous solution, containing indium (In) and a small amount of tin (Sn),with alkali to co-precipitate indium and tin hydroxides, and heating andsintering the indium and tin hydroxides under atmospheric air to produceoxide compounds. However, the ITO powder thusly produced has adisadvantage in that it does not efficiently block the infrared ray eventhough the ITO powder has excellent transparency within a visible raywavelength range, because excellent infrared blocking efficiency of theITO powder is ensured at the wavelength range of 1000 nm or more.

Furthermore, it is widely known that a color of the ITO powder is yellowwhen it is oxidized, and is blue when it is partially reduced.Accordingly, when the ITO powder, including particles with a particlesize of 100 nm or less, is dissolved in a coating liquid and then coatedon a base, the coated surface is not transparent but has an opaque whitecolor. Hence, it is difficult to apply the ITO powder to the transparentbase.

Therefore, there remains a need to develop the ITO powder having anexcellent infrared blocking effect. With respect to this, a conventionalmethod of producing an infrared blocking ITO powder is disclosed inKorean Pat. Publication No. 01-0214428, in which a co-precipitate ofindium and tin is sintered under a pressurized inert gas.

However, the above conventional method is disadvantageous in thatproduction costs are relatively high, explosion easily occurs, andproductivity is poor because the ITO powder is produced at a relativelyhigh pressure of 5 to 60 kgf/cm².

Other disadvantages of the conventional method are that when only thepartially reduced ITO powder is used, a chromaticity coordinate hazeproblem occurs and the ITO powder is easily oxidized under atmosphericair.

In the case of using only ATO, when the infrared blocking ability isimproved, the powder has very low transparency within the visible raywavelength range, and thus, it is practically difficult to commercializethe powder.

Further, in the case of using a powder mixture, containing ITO and ATOpowders mechanically mixed with each other, when a sufficiently manyamount of ATO powder is used to compensate for problems caused by theITO powder, the infrared blocking ability is reduced and thetransmissivity is reduced at the visible ray wavelength range. On theother hand, when a small amount of ATO powder is mixed with the ITOpowder, it is impossible to overcome the problems, such as thechromaticity coordinate haze problem and the oxidation of the ITO powderunder atmospheric air, occurring in use of the ITO powder.

DISCLOSURE Technical Problem

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the prior art, and an object of the presentinvention is to provide infrared blocking powder, which has therelatively high transmissivity within a visible ray wavelength range andeffectively blocks infrared rays, and which has excellent color textileand secures a stable infrared blocking effect. In addition, the presentinvention provides infrared blocking solution using the infraredblocking powder, and infrared blocking material using the infraredblocking solution.

Another object of the present invention is to provide infrared blockingpowder, which can be mass-produced at relatively low costs, infraredblocking solution using the infrared blocking powder, and infraredblocking material using the infrared blocking solution.

Technical Solution

Leading to the present invention, the intensive and various researchesinto improvement of the infrared blocking powder, carried out by thepresent inventors aiming to solve the problems encountered in the priorarts, resulted in the finding that it is difficult to effectively blocknear-infrared rays using conventional ITO and ATO powders. Accordingly,the present inventors adopted a novel method of producing the ITOpowder, having excellent infrared blocking ability, in order to avoidconventional problems caused by metal oxides.

In other words, the present inventors accomplished the infrared blockingpowder, having the excellent infrared blocking ability, according to anovel method, instead of a typical ITO powder production method as knownto those skilled in the art.

Based on the present invention, the above objects can be accomplished byproviding the infrared blocking powder, which is IATO powder. In thisregard, antimony is used to avoid a haze problem when the powder isapplied to a base, to be coated, and to control a color of the powder,and tin and indium is used to improve the infrared blocking ability.Additionally, indium, antimony, and tin are co-precipitated while beingmixed with each other in a predetermined mixing ratio to produce theIATO powder without mechanically mixing ITO powder and ATO powder witheach other. Accordingly, the IATO powder has better performance andstability than the ITO and ATO powders.

In order to accomplish the above objects, the present invention providesa novel infrared blocking powder. In this regard, an infrared blockingpowder can be produced by forming a mixture of an indium salt, anantimony salt and a tin salt in a mixing ratio of 15 to 90 wt %:1 to 20wt %:5 to 80 wt %, dissolving the mixture in water, adding a growthinhibitor and a basic solution into the water having the dissolvedmixture to precipitate powder, rinsing the powder, drying the rinsedpowder, and sintering the dried powder.

At this time, the indium salt, the antimony salt and the tin salt maydesirably be indium nitrate (In(NO3)3), antimony chloride (SbCl3) andtin chloride (SnCl2), respectively.

In addition, it is preferable that the sintering of the dried powder isconducted at 400 to 1000° C. under an oxygen-free hydrogen atmosphere.

Further, the present invention provides an infrared blocking solution,which includes the infrared blocking powder dispersed in a solvent. Atthis time, the solvent can be selected from the group consisting ofalcohol, water, organic solvent, and a mixture thereof.

In this respect, it is preferable that the infrared blocking powder hasa particle size of 5 to 200 nm.

Furthermore, the present invention provides infrared blocking solution,which includes the infrared blocking powder, solvent, conductivepolymer, organic dispersion agent, and photoinitiator.

At this time, it is preferable that the infrared blocking powder has aparticle size of 5 to 200 nm.

As well, a content of the infrared blocking powder is preferably 5 to 70wt % in the infrared blocking solution.

Moreover, the present invention provides infrared blocking material,which is produced by coating the infrared blocking solution on a surfaceof a base.

With respect to this, it is preferable that an adhesive layer be formedon any one side of the infrared blocking material coated on the base.

Advantageous Effect

According to the present invention, aqueous compounds of indium,antimony, and tin are co-precipitated to produce a novel concept ofinfrared blocking powder, that is, indium antimony tin oxide (IATO)powder, and infrared blocking solution and infrared blocking materialare produced using the IATO powder. Therefore, the IATO powder of thepresent invention has the relatively high transmissivity within avisible ray wavelength range and effectively blocks infrared rays, andwhich has excellent color textile and secures a stable infrared blockingeffect.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 illustrates light transmission spectrum curves according toexamples 2, 4, and 6 of the present invention;

FIG. 2 illustrates light transmission spectrum curves according tocomparative examples 2, 4, 6, and 8 of the present invention; and

FIG. 3 illustrates light transmission spectrum curves according tocomparative examples 9 and 10 of the present invention.

MODE FOR INVENTION

Having generally described this invention, a further understanding canbe obtained by reference to examples and comparative examples which areprovided herein for the purposes of illustration only and are notintended to be limiting unless otherwise specified.

Infrared blocking indices, visible ray transmissivities, and physicalproperties of samples according to examples of the present invention areevaluated as follows.

Light transmission spectra of infrared blocking powder and a coatedfilm, acting as infrared blocking material, are measured within awavelength range of 2500 nm using UV-3100PC manufactured by ShimadzuCorp., chromaticities and color purities of the powder and coated filmare measured using DARSA-5000 system manufactured by PSI TECH Inc., andhazes of the powder and coated film are measured using a Hazemeter.Additionally, the strength of the coated film is measured using ahardness measuring device for a pencil manufactured by Optical PrecisionCorp.

In producing IATO powder, a mixing ratio of indium, antimony, and tin is90:5:5 (A), 45:5:50 (B), and 15:5:80 (C) based on 100 parts by weight ofthe IATO powder. At this time, the mixing ratio is for the purpose ofdescribing particular embodiments only and is not intended to belimiting.

During the production of infrared blocking solution, when a particlesize of the infrared blocking powder is more than 200 nm, thetransparency of the infrared blocking solution is reduced and the hazeis undesirably increased within a visible ray wavelength range.Accordingly, the particle size of the powder is set to 100 nm or less inexamples of the present invention.

Furthermore, when the particle size of the powder is more than 200 nm,the transmissivity of the visible ray through the infrared blockingsolution is less than 40%, and the haze of the infrared blockingsolution is relatively high, and thus, it is practically impossible tocommercialize the infrared blocking powder. On the other hand, when theparticle size of the powder is less than 5 nm, the production of thepowder is not easily conducted, and thus, the productivity is reduced.

In examples and comparative examples, the strengths of coated films are2 H or more, and the hazes are less than 2.

[Production of the Infrared Blocking Powder]

According to the present invention, indium, antimony, and tin are mixedwith each other in various mixing ratios in accordance with the use ofeach infrared blocking powder to produce infrared blocking powders.

Aqueous compounds of metals, used in a co-precipitation process ofproducing the infrared blocking powders, are exemplified by nitrides,chlorides, acetates, and sulfides. In addition, examples of a basicaqueous solution, used in the hydrolysis, include hydroxides of alkalinemetals, amines, and ammoniums. Further, the excessive growth ofparticles during a reaction of indium, antimony, and tin is effectivelycontrolled using materials, chelated on surfaces of particlesconstituting the powder, such as sodium acetyl acetonate and polyacrylicacid (manufactured by Aldrich Chemical Co. and having a molecular weightof 2000).

In other words, aqueous compounds of indium, antimony, and tin are mixedwith each other in a predetermined mixing ratio, and then dissolved inwater. A growth inhibitor and the basic aqueous solution are added intothe mixed solution to co-precipitate powder, the co-precipitate powdercontaining moisture is rinsed and then dried. The dried co-precipitatepowder is sintered under an oxygen-free hydrogen atmosphere, therebyaccomplishing the infrared blocking powder.

As described above, the present invention provides a novel concept ofindium antimony tin oxide (IATO) powder, the infrared blocking powder,produced by co-precipitating the aqueous compounds of indium (In),antimony (Sb), and tin (Sn) so that indium is doped with antimony andtin.

A better understanding of the IATO powder according to the presentinvention may be obtained through the following example 1 which is setforth to illustrate, but is not to be construed as the limit of thepresent invention.

In the examples of the present invention, ultrafine powder, having theparticle size of 10 to 50 nm, is used as the infrared blocking powder(IATO), a mixture of 25.2 parts by weight of methyl ethyl ketone (MEK)and 10.8 parts by weight of toluene is used as a dispersion media, 20parts by weight of acrylate oligomer (EB-9970 manufactured by SK UCBCorp.) is used as a resin, acetate-based disperbyk-170, manufactured byBYK-Chemie Inc., is used as a dispersion agent, and hydroyketone-basedIrgacure 184, manufactured by Ciba Specialty Chemicals Inc., is used asa photoinitiator.

EXAMPLE 1

Indium salts, antimony salts, and tin salts were mixed with each otherin a mixing ratio of 15 to 90 wt %:1 to 20 wt %:5 to 80 wt %, anddissolved in water. Preferably, indium nitrate (In(NO₃)₃), antimonychloride (SbCl₃) and tin chloride (SnCl₂) were mixed with each other inthe mixing ratio of 90:5:5 (weight ratio), and dissolved in water. Afterthe completion of the dissolution of the indium salts, the antimonysalts and the tin salts in water, sodium acetylacetonate, acting as agrowth inhibitor, and a caustic soda aqueous solution, acting as a basicsolution, were added in a predetermined equivalence ratio into the mixedsolution to form a powder co-precipitate.

The co-precipitate, containing moisture, was rinsed with distilledwater, dried, and sintered at 400 to 1000° C. under an oxygen-freehydrogen atmosphere to produce reduced IATO powder (A), therebyaccomplishing infrared blocking powder according to the presentinvention.

In this respect, it is preferable that a sintering temperature be 400 to800° C. When the sintering temperature is higher than 1000° C., thegrowth of particles, constituting the infrared blocking powder, issignificantly increased, preventing the uniform dispersion of theparticles in a paste, produced using the infrared blocking powder andcoated on a base, to reduce the transparency of paste.

Furthermore, the present invention provides infrared blocking solution,which is produced by dispersing the infrared blocking powder in anorganic or inorganic resin (matrix), and which is coated on the baseaccording to a predetermined coating process.

At this time, the infrared blocking solution according to the presentinvention is produced by dispersing the infrared blocking powder insolvent, selected from the group consisting of alcohol, water, organicsolvent, and a mixture thereof.

A detailed description will be given of the production of the infraredblocking solution, below.

[Production of the Infrared Blocking Solution]

IATO powders, produced by mixing indium, antimony, and tin with eachother in various mixing ratios, are mixed with solvent and conductivepolymer to produce infrared and ultraviolet blocking coating solution.

The IATO content in the solution is 5 to 70 wt %, and the content of thesolvent, containing the conductive polymer, in the solution is 30 to 95wt %. Additionally, dispersion liquid, containing 1 to 10 wt % oforganic dispersion agent, acting as an adhesion and storage stabilitypromoter, and 0.1 to 10 wt % of photoinitiator, is added into theinfrared and ultraviolet blocking coating solution.

The infrared and ultraviolet blocking coating solution according to thepresent invention is advantageous in that the transparency is excellentwithin a visible ray wavelength range, infrared and ultraviolet rays areeffectively blocked, and the solution ensures excellent storagestability, strength of a coated film, and coating ability.

Any one of water, alcohol, and organic solvent may be applied as thesolvent to the infrared blocking solution as long as the solvent has nonegative affect the environment.

Illustrative, but non-limiting examples of the organic solvent mayinclude alcohols, such as methanol, ethanol, isopropanol, butanol, ethylcellosolve, methyl cellosolve, and diacetonealcohol, ketones, such asmethyl ethyl ketone, isobutyl ketone, and methyl isobutyl ketone, andbenzenes, such as benzene, toluene, and xylene.

In this regard, one kind of organic solvent may be used, or acombination of different organic solvents with different boiling pointsmay be used to maintain uniformity of the coated film.

The organic or inorganic resin may be exemplified by aphoto-polymerizable prepolymer or a photo-polymerizable monomer.

The photo-polymerizable prepolymer may be classified into aradical-polymerization type of prepolymer and a cation-polymerizationtype of prepolymer. In this regard, examples of theradical-polymerization type of prepolymer include polyester acrylates,epoxy acrylates, urethane acrylates, and polyol acrylates.

At this time, one kind of photo-polymerizable prepolymer, or acombination of two or more kinds of photo-polymerizable prepolymers maybe used to produce the infrared blocking solution.

Typically, an epoxy-based resin is used as the cation-polymerizationtype of prepolymer. Furthermore, examples of the photo-polymerizablemonomer include multifunctional acrylate, such as 1,4-butandioldi(metha)acrylate, 1,6-hexanediol di(metha)acrylate, neopentyl glycoldi(metha)acrylate, polyethylene glycol di(metha)acrylate, neopentylglycol adipate di(metha)acrylate, hydroxypivalate neopentyl glycoldi(metha)acrylate, dicyclopentanyl di(metha)acrylate, caprolactonedeformed dicyclopentenyl di(metha)acrylate, ethylene oxide deformedphosphate di(metha)acrylate, alkylated cyclohexyl di(metha)acrylate,isocyanurate di(metha)acrylate, trimethylol propane tri(metha)acrylate,dipentaerithritol tri(metha)acrylate, propionate deformeddipentaerithritol (metha)acrylate, tris(acryloxyethyl) isocyanurate, andpropionate deformed dipentaerithritol pantri(metha)acrylate.

One kind of photo-polymerizable monomer, or a combination of two or morekinds of photo-polymerizable monomers may be used to produce theinfrared blocking solution. Additionally, the photo-polymerizablemonomer may be used in conjunction with the photo-polymerizableprepolymer.

Examples of the photoinitiator for the radical-polymerization type ofprepolymer or the photo-polymerizable monomer include benzoin, benzoinmethyl ether, benzoin ethyl ether, benzoin isopropyl ether,benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone,2-methyl-1[4-(methylthio)phenyl]-2 morpolino-propane-1-on,4-(2-hydroxyethoxy)phenyl-2(hydroxy-2-propyl)ketone, benzophenone,P-phenylbenzophenone, dichlorobenzophenone, 2-methylanthraquinone,acetphenone dimethylketal, and P-dimethylamine benzoic acid ester.Further, the photoinitiator for the cation-polymerization type ofprepolymer is exemplified by compounds including oniums, such asaromatic sulfonium ions, aromatic oxosulfonium ions, and aromaticiodnium ions, and anions, such as tetrafluoroborate,hexafluorophosphate, hexafluoroantimonate, and hexafluoroarsenat.

At this time, one kind of photoinitiator, or a combination of two ormore kinds of photoinitiators may be used to produce the infraredblocking solution. As well, an amount of the photoinitiator in theinfrared blocking solution is 0.2 to 10 parts by weight based on 100parts by weight of the photo-polymerizable prepolymer andphoto-polymerizable monomer.

The infrared blocking solution according to the present invention willbe exemplified by the following example 2.

EXAMPLE 2

40 parts by weight of infrared blocking IATO powder, produced accordingto example 1, was added into solvent containing 25.2 parts by weight ofmethyl ethyl ketone and 10.8 parts by weight of toluene mixed with eachother. 20 parts by weight of acrylate oligomer (EB-9970 manufactured bySK UCB Corp.) was added into the resulting solvent, and 3 parts byweight of dispersion agent was then added into a mixed solution in anamount of 7 to 8% of the IATO powder. The resulting mixture wasdispersed in coating liquid using a ball mill device. When the particlesize of the IATO powder was 100 nm, 1 parts by weight of photoinitiatorwas added into the resulting coating liquid while the resulting coatingliquid being sufficiently agitated, thereby accomplishing paste-likeinfrared blocking solution containing 40% of solids.

Meanwhile, the present invention provides infrared blocking materialusing the infrared blocking solution.

With respect to this, the IATO powder is dispersed in the organic orinorganic resin (matrix), coated on the base according to apredetermined coating process, dried, and cured to produce the infraredblocking material according to the present invention.

In other words, the infrared blocking solution is coated on the base toform a film, acting as the infrared blocking material, on the base. Atthis time, the infrared blocking solution may be coated on any one orboth sides of the base, and an adhesive layer may be formed on thesolution-coated side or another side, on which the infrared blockingsolution is not coated, of the base.

Examples of the coating process include a bar coating process, a screenprinting process, a reverse coating process, a gravure coating process,a die coating process, a roll coating process, a knife coating process,and a blade coating process. Additionally, the coated film of theinfrared blocking solution may be cured by a heat curing process orirradiating UV onto the coated film.

It is preferable that the base be transparent because the infraredblocking material is transparent. Non-limiting, illustrative examples ofthe base include plastics, glasses, and ceramics.

Hereinafter, examples 3 to 7 and comparative examples 1 to 10 will bedescribed, which are for illustration purposes only and in no way limitthe scope of the present invention.

EXAMPLE 3

The infrared blocking solution, produced according to example 2, wascoated on a polyethylene terephthalate (PET) film using a bar coater,and dried at 100° C. for 3 min to form a coated layer with a thicknessof 3 μm, acting as an infrared blocking material and containing IATOpowder.

As described in the following Table 1, the transmissivity of visiblerays through the infrared blocking material was 75% or more, and thetransmissivity of infrared rays through the infrared blocking materialwas 20% or less at a wavelength of 1000 nm. Accordingly, it can be seenthat the coated layer, acting as the infrared blocking material, hadexcellent infrared blocking ability.

In a graph showing xy chromaticity of the infrared blocking material, anx value was 0.3043 and a y value was 0.3281. Furthermore, the colorpurity of the infrared blocking material was 18.2.

EXAMPLE 4

The procedure of example 1 was repeated to produce IATO powder (B)except that indium nitrate (In(NO₃)₃), antimony chloride (SbCl₃), andtin chloride (SnCl₂) were mixed with each other in a mixing ratio of45:5:50 (B).

EXAMPLE 5

Coating paste was produced using the IATO powder (B) of example 4according to the same procedure as example 3, and then coated on a baseto form a coated layer, acting as an infrared blocking material. Asdescribed in the following Table 1, the transmissivity of visible raysthrough the infrared blocking material was 75% or more, and thetransmissivity of infrared rays through the infrared blocking materialwas 50% or less at a wavelength of 1000 nm. Accordingly, it can be seenthat the coated layer, acting as the infrared blocking material, hadexcellent infrared blocking ability.

In a graph showing xy chromaticity of the infrared blocking material, anx value was 0.3109 and a y value was 0.3319. Furthermore, the colorpurity of the infrared blocking material was 16.1.

EXAMPLE 6

The procedure of example 1 was repeated to produce reduced IATOultrafine powder (C) except that indium nitrate (In(NO₃)₃), antimonychloride (SbCl₃), and tin chloride (SnCl₂) were mixed with each other ina mixing ratio of 15:5:80, and polyacrylic acid was used as a growthinhibitor.

EXAMPLE 7

Infrared blocking paste was produced using the reduced IATO powder (C)of example 6 according to the same procedure as example 3, and thencoated on a base to form a coated layer, acting as an infrared blockingmaterial. As described in the following Table 1, the transmissivity ofvisible rays through the infrared blocking material was 75% or more, andthe transmissivity of infrared rays through the infrared blockingmaterial was 65% or less at a wavelength of 1000 nm.

In a graph showing xy chromaticity of the infrared blocking material, anx value was 0.3041 and a y value was 0.3278. Furthermore, the colorpurity of the infrared blocking material was 14.5.

COMPARATIVE EXAMPLE 1

Indium nitrate (In(NO₃)₃) and tin chloride (SnCl₂) were mixed with eachother in a mixing ratio of 90:10, and then dissolved in water.

After the completion of the dissolution of indium nitrate and tinchloride in water, sodium acetylacetonate, acting as a growth inhibitor,and a caustic soda aqueous solution, acting as a basic solution, wereadded in a predetermined equivalence ratio into a mixed solution to formpowder co-precipitate.

The indium-tin co-precipitate, containing moisture, was rinsed withdistilled water, dried, and sintered at 400 to 1000° C. under anoxygen-free hydrogen atmosphere to produce blue reduced ITO powder (D).In this respect, it is preferable that a sintering temperature be 400 to800° C. When the sintering temperature is higher than 1000° C., thegrowth of particles, constituting the ITO powder, is significantlyincreased, preventing the uniform dispersion of the particles in paste,produced using the ITO powder and coated on a base, to reduce thetransparency of paste.

COMPARATIVE EXAMPLE 2

Coating paste was produced using 40 parts by weight of reduced ITOultrafine powder, containing indium and tin mixed with each other in amixing ratio of 90:10, of comparative example 1 according to the sameprocedure as example 2.

The coating paste was coated on a polyethylene terephthalate (PET) filmusing a bar coater, and dried at 100° C. to form a coated layer with athickness of 3 μm, containing the ITO powder.

The transmissivity of visible rays through the coated layer was 80% ormore, and the transmissivity of infrared rays through the coated layerwas 60% or more at a wavelength of 1000 nm.

In a graph showing xy chromaticity of the coated layer, an x value was0.3229 and a y value was 0.3416. Furthermore, the color purity of thecoated layer was a poor 3.2, and the acknowledgement quality of thecoated layer was very poor.

COMPARATIVE EXAMPLE 3

Indium nitrate (In(NO₃)₃) and tin chloride (SnCl₂) were mixed with eachother in a mixing ratio of 95:5 (E), and then dissolved in water. Afterthe completion of the dissolution of indium nitrate and tin chloride inwater, polyacrylic acid, acting as a growth inhibitor, and caustic sodaaqueous solution, acting as a basic solution, were added in apredetermined equivalence ratio into the mixed solution to form powderco-precipitate.

The indium-tin co-precipitate, containing moisture, was rinsed withdistilled water to completely remove the basic solution from theindium-tin co-precipitate, dried, and sintered at 400 to 1000° C. underan oxygen-free hydrogen atmosphere to produce blue reduced ITO powder.In this respect, it is preferable that a sintering temperature be 400 to800° C. When the sintering temperature is higher than 1000° C., thegrowth of particles, constituting the ITO powder, is significantlyincreased, preventing the uniform dispersion of the particles in paste,produced using the ITO powder and coated on a base, to reduce the thetransparency of paste.

COMPARATIVE EXAMPLE 4

A coating paste was produced using 40 parts by weight of reduced ITOultrafine powder, containing indium and tin mixed with each other in amixing ration of 95:5, of comparative example 3 according to the sameprocedure as example 2. The coating paste was coated on a polyethyleneterephthalate (PET) film using a bar coater, and dried at 100° C. toform a coated layer with a thickness of 3 μm, containing the ITO powder.At this time, the transmissivity of visible rays through the coatedlayer was 75% or more, and the transmissivity of infrared rays throughthe coated layer was 65% or more at a wavelength of 1000 nm.

In a graph showing xy chromaticity of the coated layer, an x value was0.3223 and a y value was 0.3427. Furthermore, the color purity of thecoated layer was a poor 3.4, and the acknowledgement quality of thecoated layer was very poor.

COMPARATIVE EXAMPLE 5

Indium nitrate (In(NO₃)₃) and tin chloride (SnCl₂) were mixed with eachother in a mixing ratio of 90:10, and then dissolved in water. After thecompletion of the dissolution of indium nitrate and tin chloride inwater, sodium acetylacetonate, acting as a growth inhibitor, and causticsoda aqueous solution, acting as a basic solution, were added in apredetermined equivalence ratio into a mixed solution to form a powderco-precipitate.

The indium-tin co-precipitate, containing moisture, was rinsed withdistilled water to completely remove the basic solution from theindium-tin co-precipitate, dried, and sintered at 400 to 1000° C. underan oxygen atmosphere to produce yellow oxidized ITO powder (F). In thisrespect, it is preferable that a sintering temperature be 400 to 800° C.When the sintering temperature is higher than 1000° C., the growth ofparticles, constituting the ITO powder, is significantly increased,preventing the uniform dispersion of the particles in paste, producedusing the ITO powder and coated on a base, to reduce the transparency ofpaste.

COMPARATIVE EXAMPLE 6

Coating paste was produced using 40 parts by weight of oxidized ITOultrafine powder (F), containing indium and tin mixed with each other ina mixing ration of 90:10, of comparative example 5 according to the sameprocedure as example 2.

The coating paste was coated on a polyethylene terephthalate (PET) filmusing a bar coater, and dried at 100° C. to form a coated layer with athickness of 3 μm, containing the ITO powder. At this time, thetransmissivity of visible rays through the coated layer was 75% or more,and the transmissivity of infrared rays through the coated layer was 70%or more at a wavelength of 1000 nm.

In a graph showing xy chromaticity of the coated layer, an x value was0.3223 and a y value was 0.3422. Furthermore, the color purity of thecoated layer was a poor 3.1, and the acknowledgement quality of thecoated layer was very poor.

COMPARATIVE EXAMPLE 7

Antimony chloride (SbCl₃) and tin chloride (SnCl₂) were mixed with eachother in a mixing ratio of 20:80, and then dissolved in water. After thecompletion of the dissolution of antimony chloride and tin chloride inwater, polyacrylic acid, acting as a growth inhibitor, and a causticsoda aqueous solution, acting as a basic solution, were added in apredetermined equivalence ratio into the mixed solution to form powderco-precipitate.

The antimony-tin co-precipitate, containing moisture, was rinsed withdistilled water to completely remove the basic solution from theantimony-tin co-precipitate, dried, and sintered at 400 to 1000° C.under an oxygen-free hydrogen atmosphere to produce dark blue reducedATO ultrafine powder (G). In this respect, it is preferable that asintering temperature be 400 to 800° C. When the sintering temperatureis higher than 1000° C., the growth of particles, constituting the ATOpowder, is significantly increased, preventing the uniform dispersion ofthe particles in a paste, produced using the ATO powder and coated on abase, to reduce the transparency of paste.

COMPARATIVE EXAMPLE 8

Coating paste was produced using 40 parts by weight of ATO ultrafinepowder (G), containing antimony and tin mixed with each other in amixing ratio of 20:80, of comparative example 7 according to the sameprocedure as example 4. The coating paste was coated on a polyethyleneterephthalate (PET) film using a bar coater, and dried at 100° C. toform a coated layer with a thickness of 3 μm, containing the ATO powder.

At this time, the transmissivity of visible rays through the coatedlayer was 75% or more, and the transmissivity of infrared rays throughthe coated layer was 65% or more at a wavelength of 1000 nm. In a graphshowing xy chromaticity of the coated layer, an x value was 0.2833 and ay value was 0.3088. Furthermore, the color purity of the coated layerwas 7.8.

COMPARATIVE EXAMPLE 9

Coating paste was produced using a mixture, containing the reduced ITOultrafine powder of comparative example 1 and the ATO ultrafine powderof comparative example 7 mixed with each other in a mixing ration of7:3, according to the same procedure as example 2.

The coating paste was coated on a polyethylene terephthalate (PET) filmusing a bar coater, and dried at 100° C. to form a coated layer with athickness of 3 μm, containing the ITO and ATO powders. At this time, thetransmissivity of visible rays through the coated layer was 75% or more,and the transmissivity of infrared rays through the coated layer was 60%or more at a wavelength of 1000 nm.

In a graph showing xy chromaticity of the coated layer, an x value was0.3201 and a y value was 0.3371. Furthermore, the color purity of thecoated layer was a poor 4.8, and the acknowledgement quality of thecoated layer was very poor.

COMPARATIVE EXAMPLE 10

Coating paste was produced using a mixture, containing the reduced ITOultrafine powder of comparative example 1 and the ATO ultrafine powderof comparative example 7 mixed with each other in a mixing ration of5:5, according to the same procedure as example 2.

The coating paste was coated on a polyethylene terephthalate (PET) filmusing a bar coater, and dried at 100° C. to form a coated layer with athickness of 3 μm, containing the ITO and ATO powders. At this time, thetransmissivity of visible rays through the coated layer was 75% or more,and the transmissivity of infrared rays through the coated layer was 65%or more at a wavelength of 1000 nm.

In a graph showing xy chromaticity of the coated layer, an x value was0.3031 and a y value was 0.3241. Furthermore, the color purity of thecoated layer was a poor 5.7, and the acknowledgement quality of thecoated layer was poor.

TABLE 1 XY chromaticity No. ¹Type. ²P. ³T. ⁴I. X Y ⁵Pr. Ex. 2 IATOpowder of 75 75 82 0.3043 0.3281 18.2 the present invention (A) 4 IATOpowder of 70 78 58 0.3109 0.3319 16.1 the present invention (B) 6 IATOpowder of 78 82 37 0.3041 0.3278 14.5 the present invention (C) Co. 2Reduced ITO 65 81 38 0.3229 0.3416 3.2 Ex. powder (D) 4 Reduced ITO 7375 35 0.3223 0.3427 3.4 powder (E) 6 Oxidized ITO 77 73 32 0.3223 0.34223.1 powder (F) 8 Reduced ATO 65 78 34 0.2833 0.3088 7.8 powder (G) 9Mixed type 75 75 37 0.3201 0.3371 4.8 (7:3) ITO:ATO 10 Mixed type 65 7933 0.3031 0.3241 5.7 (5:5) ITO:ATO ¹Type.: type of powder ²P.: particlesize (nm) ³T.: the transmissivity of visible rays through the coatedlayer (%) ⁴I.: blocking index of infrared rays (%) (at the wavelength of1000 nm) ⁵Pr.: the color purity of the coated layer

INDUSTRIAL APPLICABILITY

As described above, the present invention provides infrared blockingmaterial, which has various infrared blocking functions, and excellentcolor texture and transparency by properly controlling a mixing ratio ofindium, antimony, and tin. At this time, the infrared blocking materialcan be mass-produced at relatively low cost.

The present invention has been described in an illustrative manner, andit is to be understood that the terminology used is intended to be inthe nature of description rather than of limitation. Many modificationsand variations of the present invention are possible in light of theabove teachings. Therefore, it is to be understood that within the scopeof the appended claims, the invention may be practiced otherwise than asspecifically described.

1. Infrared blocking powder, which is produced by forming a mixture ofan indium salt, an antimony salt, and a tin salt in a mixing ratio of 15to 90 wt %:1 to 20 wt %:5 to 80 wt %, dissolving the mixture in water,adding a growth inhibitor and a basic solution into the water having thedissolved mixture to precipitate powder, rinsing the powder, drying therinsed powder, and sintering the dried powder.
 2. The infrared blockingpowder as set forth in claim 1, wherein the indium salt, the antimonysalt and the tin salt are indium nitrate (In(NO₃)₃), antimony chloride(SbCl₃) and tin chloride (SnCl₂), respectively.
 3. The infrared blockingpowder as set forth in claim 1, wherein the sintering of the driedpowder is conducted at 400 to 1000 C under an oxygen-free hydrogenatmosphere.
 4. Infrared blocking solution, comprising: the infraredblocking powder according to claim 1, dispersed in a solvent, thesolvent being selected from the group consisting of alcohol, water, anorganic solvent, and a mixture thereof.
 5. The infrared blockingsolution as set forth in claim 4, wherein the infrared blocking powderhas a particle size of 5 to 200 nm.
 6. Infrared blocking solution,comprising: the infrared blocking powder according to claim 1; solvent;conductive polymer; organic dispersion agent; and photoinitiator.
 7. Theinfrared blocking solution as set forth in claim 6, wherein the infraredblocking powder has a particle size of 5 to 200 nm.
 8. The infraredblocking solution as set forth in claim 6, wherein a content of theinfrared blocking powder is 5 to 70 wt % in the infrared blockingsolution.
 9. Infrared blocking material, which is produced by coatingthe infrared blocking solution according to claim 6 on a surface of abase.
 10. The infrared blocking material as set forth in claim 9,wherein an adhesive layer is formed on any one side of the infraredblocking material coated on the base.
 11. Infrared blocking solution,comprising: the infrared blocking powder according claim 2, dispersed ina solvent, the solvent being selected from the group consisting ofalcohol, water, an organic solvent, and a mixture thereof.
 12. Infraredblocking solution, comprising: the infrared blocking powder accordingclaim 3, dispersed in a solvent, the solvent being selected from thegroup consisting of alcohol, water, an organic solvent, and a mixturethereof.
 13. Infrared blocking solution, comprising: the infraredblocking powder according claim 2; solvent; conductive polymer; organicdispersion agent; and photoinitiator.
 14. Infrared blocking solution,comprising: the infrared blocking powder according claim 3; solventconductive polymer; organic dispersion agent; and photoinitiator.